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NCERT solutions Science Textbook for Class 10 chapter 13 Magnetic Effects of Electric Current

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Chapter 13 - Magnetic Effects of Electric Current

Page 228

Draw magnetic field lines around a bar magnet.

Q 1 | Page 228 | view solution

Write any three properties of magnetic lines of force.

Q 2 | Page 228 | view solution

Why don’t two magnetic lines of force intersect each other?

Q 3 | Page 228 | view solution

Pages 229 - 230

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop

Q 1 | Page 229 | view solution

The magnetic field inside a long straight solenoid-carrying current

(a) is zero
(b) decreases as we move towards its end
(c) increases as we move towards its end
(d) is the same at all points

Q 3 | Page 230 | view solution

Pages 231 - 232

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)
(a) mass
(b) speed
(c) velocity
(d) momentum

Q 1 | Page 231 | view solution

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
(a) towards south
(b) towards east
(c) downward
(d) upward

Q 3 | Page 232 | view solution

Page 233

State Fleming’s left-hand rule.

Q 1 | Page 233 | view solution

What is the role of the split ring in an electric motor?

Q 3 | Page 233 | view solution

Page 236

Explain different ways to induce current in a coil.

Q 1 | Page 236 | view solution

Page 237

 State the principle of an electric generator.

Q 1 | Page 237 | view solution

Name some sources of direct current.

Q 2 | Page 237 | view solution

Which sources produce alternating current?

Q 3 | Page 237 | view solution

A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each

(a) two revolutions
(b) one revolution
(c) half revolution
(d) one-fourth revolution

Q 4 | Page 237 | view solution

Page 238

Name two safety measures commonly used in electric circuits and appliances.

Q 1 | Page 238 | view solution

An electric oven of 2 kW is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain.

Q 2 | Page 238 | view solution

What precaution should be taken to avoid the overloading of domestic electric circuits?

Q 3 | Page 238 | view solution

Pages 240 - 241

Which of the following correctly describes the magnetic field near a long straight wire?
(a) The field consists of straight lines perpendicular to the wire
(b) The field consists of straight lines parallel to the wire
(c) The field consists of radial lines originating from the wire
(d) The field consists of concentric circles centred on the wire

Q 1 | Page 240 | view solution

The phenomenon of electromagnetic induction is
(a) the process of charging a body
(b) the process of generating magnetic field due to a current passing through a coil
(c) producing induced current in a coil due to relative motion between a magnet and the coil
(d) the process of rotating a coil of an electric motor

Q 2 | Page 240 | view solution

The device used for producing electric current is called a
(a) generator
(b) galvanometer
(c) ammeter
(d) motor

Q 3 | Page 240 | view solution

The essential difference between an AC generator and a DC generator is that
(a) AC generator has an electromagnet while a DC generator has permanent magnet.
(b) DC generator will generate a higher voltage.
(c) AC generator will generate a higher voltage.
(d) AC generator has slip rings while the DC generator has a commutator.

Q 4 | Page 240 | view solution

 At the time of short circuit, the current in the circuit
(a) reduces substantially
(b) does not change
(c) increases heavily
(d) vary continuously

Q 5 | Page 240 | view solution

 State whether the following statements are true or false.

An electric motor converts mechanical energy into electrical energy.

Q 6.1 | Page 240 | view solution

State whether the following statements are true or false.

An electric motor converts mechanical energy into electrical energy.

Q 6.2 | Page 240 | view solution

State whether the following statements are true or false

The field at the centre of a long circular coil carrying current will be parallel straight lines

Q 6.3 | Page 240 | view solution

State whether the following statements are true or false.

 A wire with a green insulation is usually the live wire of an electric supply.

Q 6.4 | Page 240 | view solution

List three sources of magnetic fields.

Q 7 | Page 240 | view solution

How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.

Q 8 | Page 241 | view solution

When is the force experienced by a current-carrying conductor placed in a magnetic field largest?

Q 9 | Page 241 | view solution

Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?

Q 10 | Page 241 | view solution

Draw figure ‘Electric motor’ and working 

Q 11.1 | Page 241 | view solution

Principle of Electric motor

Q 11.2 | Page 241 | view solution

Name some devices in which electric motors are used

Q 12 | Page 241 | view solution

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil, (ii) withdrawn from inside the coil, (iii) held stationary inside the coil?

Q 13 | Page 241 | view solution

 Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.

Q 14 | Page 241 | view solution

State the rule to determine the direction of a force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it

Q 15 | Page 241 | view solution

State the rule to determine the direction of a current induced in a coil due to its rotation in a magnetic field

Q 15 | Page 241 | view solution

State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current

Q 15 | Page 241 | view solution

Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?

Q 16 | Page 241 | view solution

What happens to the flow of electric current during a short circuit?

Q 17 | Page 241 | view solution

What is the function of an earth wire? Why is it necessary to earth metallic appliances?

Q 18 | Page 241 | view solution

Extra questions

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)

view solution

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